Background: We have previously shown that instillation of 200mg/kg of porcine surfactant (Curosurfâ„¢) induces a systemic vasodilation in surfactant depleted newborn piglets. In the present work we wanted to study if this effect is dependent on dose and further could be induced also by instillation of a bovine surfactant preparation(Survantaâ„¢).

Subjects: Twenty two 3-5-d old piglets

Interventions: Arterial and venous catheters for pressure measurements. Left sided thoracotomy and placement of flow probe around the common pulmonary artery for measurements of cardiac output. Repeated saline lung lavage and then randomization to one of three groups. Through the endotracheal tube instillation of either Curosurf 100 mg/kg (n=8), Curosurf 200 mg/kg (n=7) or Survanta 100 mg/kg (n=7) was done.

Results: Systemic vascular resistance decreased 7 (±4)%, 18 (±6)% and 15 (±12)% in the three groups respectively (p < 0.05 compared to before instillation in all three groups). A significant difference between the high and low dose Curosurf groups was found (p < 0.05), whereas no significant difference was seen between the Curosurf 100 mg group and the Survanta group. The decrease in vascular resistance was compensated by an increase in cardiac output, resulting in stable arterial blood pressures.

Conclusion: Both modified porcine and modified bovine lung surfactant preparations induce a significant decrease in systemic vascular resistance in surfactant depleted newborn piglets. A more pronounced effect is observed after 200 mg/kg than after 100 mg/kg of porcine surfactant.